Delphi API monitoring with Frida, Part 3

February 20, 2022 in Frida, Malware Analysis

In part 1 and part 2 we looked at individual APIs and I hinted we can automate generation of handlers. Today we will do exactly that.

The attached python code (delphi.py) reads PE file and then searches for code patterns that represent a couple of popular Delphi API functions responsible for string operations.

For every occurrence found, we generate a handler & print out the offsets (first offset is file position, and the second number is RVA that we need to pass to frida-trace):

Once handlers are generated, we can run frida-trace:

frida-trace c:\test\foo.exe foo.exe -a foo.exe!4c04 -a foo.exe!4e70 -a foo.exe!4fac -a foo.exe!4c48

This is a full log. Lots of string goodness, right? Note the IOCs, and the fact processes seem to be enumerated in order to find if possibly targeted processes are present.

And in case you are wondering the sample in question (foo.exe) is 00008EB74EEAEFFC64E85F8B0978D4EB056FCF390264A0D4C7D4A15ED5356DD3.

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